Pack-Year Calculator
Calculate cumulative tobacco exposure in pack-years to assess smoking history and health risks. Used for clinical assessment and lung cancer screening eligibility.
Smoking History Information
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Enter your smoking history to calculate pack-years and assess health risks
What is a Pack-Year?
One pack-year equals smoking 20 cigarettes (1 pack) per day for 1 year, or 7,300 cigarettes total. It's a standardized measure of cumulative tobacco exposure used in clinical settings.
Screening Eligibility
Adults aged 50-80 with a 20+ pack-year smoking history are typically eligible for annual lung cancer screening with low-dose CT, according to USPSTF guidelines.
Clinical Importance
Pack-year history is crucial for assessing risk of lung cancer, COPD, cardiovascular disease, and other smoking-related conditions. It helps guide screening and prevention strategies.
Formulas
Standard Formula
Pack-years = (cigarettes per day / 20) × years smoked
Alternative Formula
Pack-years = packs per day × years smoked